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authorOleg Nesterov <oleg@tv-sign.ru>2005-06-23 03:09:00 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 12:45:17 -0400
commitf972be33ce6a08b5f096ba013c7459a3a82f5f39 (patch)
tree5d495cdfc82dce1b8017244563f2f5437c395433 /kernel/posix-timers.c
parentfd450b7318b75343fd76b3d95416853e34e72c95 (diff)
[PATCH] posix-timers: use try_to_del_timer_sync()
sys_timer_settime/sys_timer_delete needs to delete k_itimer->real.timer synchronously while holding ->it_lock, which is also locked in posix_timer_fn. This patch removes timer_active/set_timer_inactive which plays with timer_list's internals in favour of using try_to_del_timer_sync(), which was introduced in the previous patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/posix-timers.c')
-rw-r--r--kernel/posix-timers.c34
1 files changed, 7 insertions, 27 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index cabb63fc9e16..5b7b4736d82b 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -89,23 +89,6 @@ static struct idr posix_timers_id;
89static DEFINE_SPINLOCK(idr_lock); 89static DEFINE_SPINLOCK(idr_lock);
90 90
91/* 91/*
92 * Just because the timer is not in the timer list does NOT mean it is
93 * inactive. It could be in the "fire" routine getting a new expire time.
94 */
95#define TIMER_INACTIVE 1
96
97#ifdef CONFIG_SMP
98# define timer_active(tmr) \
99 ((tmr)->it.real.timer.entry.prev != (void *)TIMER_INACTIVE)
100# define set_timer_inactive(tmr) \
101 do { \
102 (tmr)->it.real.timer.entry.prev = (void *)TIMER_INACTIVE; \
103 } while (0)
104#else
105# define timer_active(tmr) BARFY // error to use outside of SMP
106# define set_timer_inactive(tmr) do { } while (0)
107#endif
108/*
109 * we assume that the new SIGEV_THREAD_ID shares no bits with the other 92 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
110 * SIGEV values. Here we put out an error if this assumption fails. 93 * SIGEV values. Here we put out an error if this assumption fails.
111 */ 94 */
@@ -226,7 +209,6 @@ static inline int common_timer_create(struct k_itimer *new_timer)
226 init_timer(&new_timer->it.real.timer); 209 init_timer(&new_timer->it.real.timer);
227 new_timer->it.real.timer.data = (unsigned long) new_timer; 210 new_timer->it.real.timer.data = (unsigned long) new_timer;
228 new_timer->it.real.timer.function = posix_timer_fn; 211 new_timer->it.real.timer.function = posix_timer_fn;
229 set_timer_inactive(new_timer);
230 return 0; 212 return 0;
231} 213}
232 214
@@ -480,7 +462,6 @@ static void posix_timer_fn(unsigned long __data)
480 int do_notify = 1; 462 int do_notify = 1;
481 463
482 spin_lock_irqsave(&timr->it_lock, flags); 464 spin_lock_irqsave(&timr->it_lock, flags);
483 set_timer_inactive(timr);
484 if (!list_empty(&timr->it.real.abs_timer_entry)) { 465 if (!list_empty(&timr->it.real.abs_timer_entry)) {
485 spin_lock(&abs_list.lock); 466 spin_lock(&abs_list.lock);
486 do { 467 do {
@@ -983,8 +964,8 @@ common_timer_set(struct k_itimer *timr, int flags,
983 * careful here. If smp we could be in the "fire" routine which will 964 * careful here. If smp we could be in the "fire" routine which will
984 * be spinning as we hold the lock. But this is ONLY an SMP issue. 965 * be spinning as we hold the lock. But this is ONLY an SMP issue.
985 */ 966 */
967 if (try_to_del_timer_sync(&timr->it.real.timer) < 0) {
986#ifdef CONFIG_SMP 968#ifdef CONFIG_SMP
987 if (timer_active(timr) && !del_timer(&timr->it.real.timer))
988 /* 969 /*
989 * It can only be active if on an other cpu. Since 970 * It can only be active if on an other cpu. Since
990 * we have cleared the interval stuff above, it should 971 * we have cleared the interval stuff above, it should
@@ -994,11 +975,9 @@ common_timer_set(struct k_itimer *timr, int flags,
994 * a "retry" exit status. 975 * a "retry" exit status.
995 */ 976 */
996 return TIMER_RETRY; 977 return TIMER_RETRY;
997
998 set_timer_inactive(timr);
999#else
1000 del_timer(&timr->it.real.timer);
1001#endif 978#endif
979 }
980
1002 remove_from_abslist(timr); 981 remove_from_abslist(timr);
1003 982
1004 timr->it_requeue_pending = (timr->it_requeue_pending + 2) & 983 timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
@@ -1083,8 +1062,9 @@ retry:
1083static inline int common_timer_del(struct k_itimer *timer) 1062static inline int common_timer_del(struct k_itimer *timer)
1084{ 1063{
1085 timer->it.real.incr = 0; 1064 timer->it.real.incr = 0;
1065
1066 if (try_to_del_timer_sync(&timer->it.real.timer) < 0) {
1086#ifdef CONFIG_SMP 1067#ifdef CONFIG_SMP
1087 if (timer_active(timer) && !del_timer(&timer->it.real.timer))
1088 /* 1068 /*
1089 * It can only be active if on an other cpu. Since 1069 * It can only be active if on an other cpu. Since
1090 * we have cleared the interval stuff above, it should 1070 * we have cleared the interval stuff above, it should
@@ -1094,9 +1074,9 @@ static inline int common_timer_del(struct k_itimer *timer)
1094 * a "retry" exit status. 1074 * a "retry" exit status.
1095 */ 1075 */
1096 return TIMER_RETRY; 1076 return TIMER_RETRY;
1097#else
1098 del_timer(&timer->it.real.timer);
1099#endif 1077#endif
1078 }
1079
1100 remove_from_abslist(timer); 1080 remove_from_abslist(timer);
1101 1081
1102 return 0; 1082 return 0;